Nuclear localization signal in nuclear receptor VDR facilitates the mitotic genome bookmarking by involving distinct amino acid residues.

Mitotic genome-bookmarking preserves epigenetic information, re-establishing progenitor's gene expression profile through transcription factors, chromatin remodelers, and histone modifiers, thereby regulating cell fate and lineage commitment post-mitotically in progeny cells. Our recent study revealed that the constitutive association of VDR with mitotic chromatin involves its DNA-binding domain. However, amino acid residues in this domain, crucial for genome bookmarking, remain elusive. This study demonstrates that nuclear localization signal (NLS) residues between 49 and 55 amino acids in VDR are essential for receptor-chromatin interaction during mitosis. Furthermore, it is revealed that both bipartite nature of VDR-NLS region and N-terminally located positively charged arginine residues are critical for its 'genome-bookmarking' property. Since mitotic chromatin association of heterodimeric partner RXR depends on VDR-chromatin association, interventions in VDR binding also abort RXR-chromatin interaction. Overall, this study documents the mechanistic details underlying VDR-chromatin interactions in genome-bookmarking behavior, potentially aiding in comprehending VDR-mediated diseases attributed to certain SNPs.

Mitotic genome-bookmarking by nuclear hormone receptors: A novel dimension in epigenetic reprogramming and disease assessment.

Arrival of multi-colored fluorescent proteins and advances in live cell imaging has immensely contributed to our understanding of intracellular trafficking of nuclear receptors and their roles in gene regulatory functions. These regulatory events need to be faithfully propagated from progenitor to progeny cells. This is corroborated by multiple converging mechanisms that include histone modifications and lately, the phenomenon of 'mitotic genome-bookmarking' by specific transcription factors. This phenomenon refers to the retention and feed-forward transmission of progenitor's architectural blueprint of active transcription status which is silenced and preserved during mitosis. Upon mitotic exit, this phenomenon ensures accurate reactivation of transcriptome, proteome, cellular traits and phenotypes in the progeny cells. In addition to diverse modes of genome-bookmarking by nuclear receptors, a correlation between disease-associated receptor polymorphism and disruption of this phenomenon is apparent. However, breakthrough technologies shall reveal finer details of this phenomenon to help achieve normalcy in receptor-specific diseases.

Mapping, clustering, and analysis of research in psychiatric genomics.

INTRODUCTION: The distribution pattern and knowledge structure of psychiatric genomics were surveyed based on literature dealing with both psychiatry and genomics/genetics. Coword analysis and bibliographic coupling of the records retrieved from Scopus and PubMed for 2016-2020 revealed the subsurface research aspects. METHOD: The data were analyzed using coword analysis and clustering methods using Sci2 and VOSviewer. RESULT: Analysis of ~3800 records showed that psychiatric genomics is, as expectedly, covered largely under biomedical subjects with a visible interest in other disciplines such as humanities and ethics. A coword analysis was done for all the years, followed by a year-wise analysis based on the keywords, and then a bibliographic coupling based on the cited references. This led to the generation of different clusters of prevalent research areas. The centrality values described the position of each component. DISCUSSION: 'Schizophrenia', 'depression', 'pharmacogenomics', and 'immunopathogenesis' were the research topics of overarching interest. 'Gut-brain axis' and 'gene-environment interaction' were the emerging topics, whereas certain topics such as 'child and adolescent psychiatry' remained priorities when compared to earlier studies. The keywords and research focus were diverse. They ranged from genetics to transcriptomics and epigenetics to proteomics of psychiatric disorders. We found a stagnation of science communication in the field with only 0.2% of the articles from the entire corpus relevant to it. The research categories identified in this study reflect the current publication and research trends in psychiatric genomics.